Opioids Not for Many Types of Chronic Pain, Researchers Say

Widely prescribed, addictive opioid medications designed to help people with chronic pain may actually have very little treatment effectiveness in many cases, the members of a National Institutes of Health (NIH) review team report.

Doctors in the U.S. increasingly prescribe powerful opioid medications as treatments for people affected by various forms of chronic pain. In an analysis published in January 2015 in the American College of Physicians’ Annals of Internal Medicine, an NIH team including researchers from six U.S. universities concluded that these medications may have relatively low chances of achieving their objectives. Since opioid medications are fairly common targets for misuse, this finding may indicate that the widespread use of prescription opioids substantially increases society’s drug-related risks without producing a clear, offsetting benefit.

Opioids and Chronic Pain

Chronic pain has a range of possible sources, including major accidents, cancer, damage in the central or peripheral nervous systems and several forms of arthritis. Opioid medications are prescription-only drugs designed to address chronic pain (and certain forms of short-term or acute pain) by disrupting the brain’s ability to receive pain signals from various parts of the body or disrupting the brain’s ability to identify incoming nerve signals as pain-causing in nature. Specific types of prescription opioids used to help people with moderate-to-severe chronic pain include oxycodone, hydrocodone, fentanyl and hydromorphone.

Opioids and Addiction

Apart from their painkilling qualities, opioid medications have the ability to trigger a powerfully pleasurable sensation called euphoria when consumed in any substantial amount. This ability stems from an opioid-induced increase in the normal levels of a chemical called dopamine inside a group of brain structures collectively known as the pleasure center. Unfortunately, when the chemical environment inside the pleasure center is repeatedly artificially altered by the presence of opioids, dopamine processing in this brain area can undergo long-term changes that make the affected individual susceptible to the onset of dependence. While doctors can potentially control dependence-related issues in patients who take their medications according to established treatment guidelines, people who misuse prescription opioids within or outside of a medical context can easily cross the threshold from opioid dependence to opioid addiction.

Frequency of Opioid Misuse

In the U.S., adults and children above the age of 11 misuse prescription opioids at a much higher rate than they abuse other prescription drugs. According to figures compiled for the year 2013 by researchers from the U.S. Department of Health and Human Services’ Substance Abuse and Mental Health Services Administration, the monthly misuse rate for prescription opioids in the preteen, teen and adult population is about 1.7 percent (compared to a 0.6 percent rate for tranquilizers, the next most commonly misused prescription medications). The rate of misuse fell by a statistically unimportant amount between 2012 and 2013.

Do Opioid Medications Address Chronic Pain?

In the analysis published in the Annals of Internal Medicine, an NIH panel with members from the University of Vermont, Johns Hopkins University, Michigan State University, Indiana University, the University of Connecticut and the University of California, Los Angeles conducted an examination of the evidence for and against the effectiveness of opioid medications as a treatment for chronic pain. This examination included an assessment of the usefulness of prescription opioids for specific types of chronic pain, as well as an assessment of the potential for collateral damage from opioid use in the form of opioid addiction or other problems such as increased heart attack risk, underproduction of testosterone and impaired sexual function.

The panel members concluded that there is little detailed evidence to support the use of opioid medications as a treatment for chronic pain. The strongest available evidence specifically indicates the use of these medications for chronic pain symptoms associated with conditions that include cancer, accidental injuries and rheumatoid arthritis. Conversely, evidence is prominently lacking for opioid-based treatment of other chronic conditions such tension headaches and fibromyalgia.

The NIH panel notes that doctors typically don’t have much to go on when trying to decide which types or amounts of opioid medication to prescribe in any given situation. The panel members also note that no one really knows the effectiveness of programs designed to reduce the odds that a person receiving opioid medications will run into significant problems. They urge doctors who treat chronic pain to widen their perspectives and establish more holistic methods of helping their patients.